Pavement-joint.



' R. D. BAKER. PAVEMENT JOINT. APPLICATION. FILED 1150.21.1915.

LWfifiQO. "Pater med Apr.l1,1916.

fiaberlga z er attomugg ROBERT D. BAKER, or'nn'fnorr, MICHIGAN.

PAVEMENT-JOINT.

' Specification of Letters Patent.

Original application filed May 13, 1912, Serial No. 696,990. Divided andthis application filed December 21, 1915. Serial No. 68,048.

To all whom it may concern:

Be it known that I, ROBERT D. BAKER, a citizen of the United States ofAmerica, re-

. siding at Detroit, in the county of Wayne 5 and State of Michigan,have invented certain new and useful Improvements in Pavement-Joints, ofwhich the followlng 1s a specification, reference being had therein to,

the accompanying drawlngs. j.

The invention relates to pavement oints,

and consists in the novel construction of an armor plate for protectingthe edges of the pavement at the joints, and in certain ar-' rangementsand combinations of parts as will more fully hereinafter appear.

As my invention is peculiarly adapted for use in concrete pavements, Iwill illustrate and describe the invention in connection with such atype of pavement.

In the drawings :,Figure 1 is a sectional perspective View .of a portionof a pavement embodying the invention; Fig. 2 is a sectlon on the linea2m of Fig. 1; and Fig. 3 1s a fragmentary perspective view of the armorplate. I

The use of concrete for constructing the pavements I find offers manyadvantages, among which is durability. However, experience has shownthat expanslon oints should be provided at regular intervals to allowfor expansion and contraction, due to variations in temperature. It isalso found that unless suitably protected, the edges of such jointsbecome worn down by the abrasions incident to traffic and weathering,causing ruts which increase in depth and width with the continuous useof the pavement. To remedy this difiiculty I protect the edges of theexpansion joints by a novel construction of armor plate.

In forming-concrete pavement the concrete mixture A is poured orotherwise suitably placed upon a suitable sub-grade B of earth. Theconcrete or pavement proper is divided at suitable intervals, say 25feet, by joints or spaces forming sections. These joints or spacespreferably extend uninterruptedly from side to side of the roadbed andpermit of independent contraction and expansion of the sections.Preferably the joints or spaces are filled with asphalt, tar or thelike. In order to protect the edges of the concrete sections at thejoint, metal plates (7 are set into the concrete at the oint.

Instead of forming the armor plate fiat on that side of the plate whichengages the concrete, I. have so constructed the plate that its innerface at the upper edge makes an obtuse angle with the upper surface ofthe section which edges it protects. This type of plate is particularlyuseful where the pavement is subjected to exceedingly severe trafficconditions, since it reduces to a minimum the possibility of theconcrete breaking away or otherwise separating from the upper edge ofthe plate, thereby preventing trafiic wearing a groove in the surface ofthe concrete at the junction of the upper edge of the plate and thepavement material.

Referring more in detail to the structure illustrated in the drawings,the plate C has a flat body portion with an overhanging ledge D formedalong its upper edge on the inner side of the plate, that is-the side ofthe plate next to the concrete. The top E of the plate is flat so as tobe flush with the top surface F of the pavement material. while thelower face G of the overhanging ledge D is beveled to insure a bevel orob tuse angle on the upper edge H of the concrete. In the structureshown the outer face I of the plate is flat, and the top E of the .istemporarily arranged a division plate which acts to form the joint orspace be tween adjacent concrete sections. The

armor plates and the division plate therebetween are suitably held inproper relation to each other and to the roadbed and then the concreteis placed upon the roadbed so that the upper surface thereof is flushwith the tops E of the plates and the latter embedded in the concrete.After the concrete. has set sufficiently the division plate is removedand the space between the sections filled with asphalt, tar or othersuitable compressible material, which will allow for expansion andcontraction of the concrete section's.

It will he 'evidentthat the manner of forming the pavement may be variedas desired, and that While the plates are peculiarly adapted forreinforcing or protecting the edges of concrete pavement at the jointsthereof, that the plates are capable of other uses.

lVhat I claim as my invention is 1. Means for protecting pavementjoints, comprising a'pair of armor plates arranged. on edge and inparallel with their adjacent faces in relatively close mutual proximity,

the outer or adjacent faces of said plates being plane and vertical,while the upper portions of the inner or non-adjacent faces flareobliquely to form thickened wearing edges.

2. The combination with adjacent pavement sections, of parallel armorplates protecting the edges of the joint between said sections, eachofthe inner or non-adjacent faces of said plates making an obtuse anglevwith the upper surface of the section whose edge it protects.

3. The combination with adjacent pavement sections, of parallel armorplates protecting the edges of the joint between said sections, each ofthe outer or non-adjacent faces of said plates making an obtuse anglewith the upper surface of the section whose edge it protects, and theinner or adjacent faces of the plates being plane and vertical. 4. Areinforcing plate for the edge of a body of concrete comprising a flatplate, means to secure this plate against the side of the body ofconcrete with its outer face vertical, and an overhanging ledge formedalong the upperedge of the plate on the side next to the concrete toprotect the edge of the concrete, the lower edge of said ledge beingbeveled so as to insure an obtuse angle on the concrete, and the entiretop of the plate being flush with the concrete and forming a right anglewith the outer face of the plate.

-5. A reinforcing plate for the edges of expansion joints betweensections of concrete roadways, comprising a vertical plate having a flatbody portion with a flat outer side and a short overhanging ledge formedalong its upper edge on the side next to the con-

